I'm creating a worksheet that will serve as a statistical analysis for
fla****er (lakes and ponds) fish species. I'm tring to calculate pooled CPUE
(Captured Per Unit Effort) for several sampling efforts (gillnetting,
electrofishing, etc) per species.

I'm hoping to use 24 samples with 17 fish species.

For example: If we fish 8 times on a lake there are 16 empty samples (24-8
= 16)...each sample has a formula to calculate the hours of effort.

So...if in sample #1 (we fish 1 gillnet for one day) we catch 3 Lake Trout
from 7/29/04 13:00 (start date) to 7/30/04 15:23 we are left with a fishing
duration of 26.38 hours. I can use these numbers to calculate a CPUE for
sample #1 (3 fish caught in 26.38 hours equals 0.114 CPUE).

My problems arise when I try to pool all of my CPUE's for one species. If
species A has only 8 efforts then there are 16 cells reading 0.00 hours of
effort. I'm hoping somehow to create a criteria page that will allow me to
differentiate between the 0.00 hours mentioned above and the 0.00 that will
occur when i fish for 12 hours and catch zero fish!

Any ideas?